Candidate Search Location with Distance from City not working

On the Candidate Search screen where I have selected the following location in Wellington, New Zealand I get the following results of 2040 items

Image 1:

When use the additional filter of Distance from City

I would expect a low number of results, but there is no change in result count. To prove that the number should be lower the candidate with Carterton, Wellington, NZ is 85.2 km away.

How does this filter work?

Thanks

Michael